Synthesis of Urazoles via Cycloaddition Employing 4-Phenyl-4H-1,2,4-Triazole-3,5-dione (PTAD) Transfer

Article abstract of DOI:10.1055/s-1986-31804

A new method was developed involving transfer of 4-phenyl-4H-1,2,4-triazole-3,5-dione (PTAD) from thermally labile urazoles 9 and 10 to bicyclic olefin derivatives 1-8, which irreversibly undergo cycloaddition accompanied by Wagner-Meerwein rearrangement.In most cases purer products and significantly improved yields of the corresponding urazoles 11-18 are obtained than by direct PTAD cycloaddition.